We start with the words of 2012, a member of the forum who follows the topic of the jailbreak of closely:
Some small news of the JB scene.MuscleNerd announced that Ultrasnow will be updated Sunday for all Idevice except the iphone4 (will come later). This update will allow the passage to IOS 4.2.1 without updating the baseband and thus being able “unlock” the idevice.
Cf MuscleNerd: @MuscleNerdMuscleNerdGood progress today...everything is on track for updated ultrasn0w by Sunday/Funday at the latest (longer for iPhone4!)
On the other side,Tuaw tells us that Apple further increased its protections with iOS 4.2.1. Henceforth, the system will check Baseband at start up (firmware of the modem modified for the desimlock) and its signature and will be able to refuse to start the telephone if it was modified. One can suppose that this protection will not hold indefinitely either.
